A variety of dispensing systems have been developed for dispensing a fluent material product, such as pharmaceutical fluids, beverages, and personal care products such as soap, from a supply system. Such a supply system (which could be, or include, a container) typically has a discharge end that includes a dispensing end structure which may be a unitary part of the supply system or a separate closure that is releasably or permanently mounted to the container or other supply system.
One type of conventional dispensing end structure used with containers has a flow control element in the form of a flexible, pressure-openable, self-sealing, slit-type dispensing valve mounted in the end structure over the container opening. The term “pressure-openable refers to a valve which opens when a sufficient pressure differential is applied across the valve (e.g., as by increasing the pressure on one side and/or decreasing the pressure on the other side). Such a valve is typically used on a container which has a flexible, but resilient, wall or walls. When the container is squeezed, the pressure inside the container increases. This causes the valve slit or slits to open, and the fluent material product contents of the container are discharged through the open valve. Typically, the valve automatically closes to shut off fluid flow upon removal of the increased pressure—even if the container is inverted and the closed valve is subject to the weight of the contents within the container. Designs of such valves are illustrated in the U.S. Pat. Nos. 5,271,531, 5,033,655, and 4,931,775.
When a separate dispensing closure is employed for attachment to the container, the closure typically includes a body mounted on the container to hold the valve over the container opening. A lid can be provided for engaging the closure body to cover the valve during shipping and when the container is otherwise not in use. See, for example, FIGS. 31–34 of U.S. Pat. No. 5,271,531. Such a lid can be designed to prevent leakage from the valve under certain conditions. The lid can also keep dust and dirt away from the valve and/or can protect the valve from damage.
The inventors of the present invention have determined that it would be advantageous to provide a new type of flow control element for use in, or as part of, a dispensing structure or closure that can provide certain operational advantages. It would be particularly beneficial to provide such an improved flow control element with the capability for dispensing a fluent material product while at the same time accommodating in-venting of another (e.g., second) fluent material (e.g., ambient air) into the container or other supply system so as to minimize or eliminate interruption of the discharging flow of the fluent material product.
Such an improved flow control element should preferably also have the capability of creating a seal between the surrounding environment (e.g., atmosphere) and the product when the flow control element is closed so as to protect the fluent material product from contamination and/or dehydration.
Further, it would be beneficial if such an improved flow control element could function as a part of a closure or other dispensing structure that does not necessarily require the use of a lid.
It would also be desirable to provide a flow control element that could be incorporated in a dispensing closure for the package (e.g., the package consisting of a container, product in the container, and the dispensing end structure on the container) and that would permit the user to invert the package without product leakage prior to dispensing, thereby providing the user with more control over the product dispensing operation.
It would also be desirable if such an improved flow control element could be readily retained in a closure that could optionally accommodate the employment of an auxiliary lid and/or frangible, tamper-evident cover or tear band.
An improved flow control element should also accommodate designs which permit incorporation of the element as a unitary part, or extension, of the container (or other supply system), as well as designs that separately mount the dispensing structure or closure on the container (or other supply system) in a removable or non-removable manner.
It would also be beneficial if such an improved flow control element, either alone or as part of a dispensing structure, could readily accommodate its manufacture from a variety of different materials.
Further, it would be desirable if such an improved flow control element, and any associated dispensing end structure incorporating the element, could be provided with a design that would accommodate efficient, high-quality, large volume manufacturing techniques with a reduced product reject rate.
Preferably, the design of the improved flow control element and dispensing structure should also accommodate high-speed manufacturing techniques that can produce products with consistent operating characteristics unit-to-unit with high reliability.
The present invention provides an improved flow control element and associated dispensing structure which can accommodate designs having one or more of the above-discussed benefits and features.